光子电子能量沉积的快速MC模拟方法  

High-Efficiency Monte Carlo Simulation Method on Energy Deposition of Photon and Electron

作　　者：邱有恒[1,2] 应阳君[1] 王敏[1] 陈行良[1] 

机构地区：[1]北京应用物理与计算数学研究所,北京100094 [2]中国工程物理研究院研究生部,北京100088

出　　处：《核动力工程》2010年第S2期171-174,共4页Nuclear Power Engineering

摘　　要：蒙特卡罗程序(MCNP)采用*F8统计光子电子能量沉积。针对*F8计算效率低、设置截断能大小未知的特点,给出了一种新的光子电子能量沉积统计方法以及加速计算技巧。新方法的基本思想是在电子随机游动过程中每一步,根据电子所在位置、能量判断剩余能量电子能否逃出该网格,如果不能,就截断电子并将剩余能量全部沉积在该网格内。与MCNP程序中的光子电子能量沉积模拟方法相比,新方法自动截断电子,无需人为干预,使用方便,计算效率与精度兼顾更好。MCNP program counts the energy deposition of photon and electron by the *F8 method.The computational efficiency of *F8 is very low.With a high cutoff energy of electron,the efficiency of *F8 will be greatly increased,but the precision may be decreased.And the appropriate cutoff energy is unknown.A new calculation method and speedup technique of photon and electron energy deposition are introduced in this paper.The new method merely counts the energy loss of electron collision,whether a electron will be cutoff or not rest with the electron energy and position in the speedup technique.Compared to the method used in MCNP program,the calculation efficiency is increased and the precision is very high in our new method.It is the most important character that the cutoff energy of electron is selected automatically in the speedup technique.

关 键 词：能量沉积 X射线 蒙特卡罗程序 放射医疗 

分 类 号：TL329.2[核科学技术—核技术及应用]